Merge branch 'master' into jgrpp

# Conflicts:
#	src/autoreplace_gui.cpp
#	src/build_vehicle_gui.cpp
#	src/cheat_gui.cpp
#	src/company_gui.cpp
#	src/debug.cpp
#	src/engine_gui.h
#	src/error_gui.cpp
#	src/group_gui.cpp
#	src/industry_cmd.cpp
#	src/industry_gui.cpp
#	src/misc_gui.cpp
#	src/network/network_gui.cpp
#	src/newgrf.cpp
#	src/newgrf_debug_gui.cpp
#	src/newgrf_gui.cpp
#	src/order_gui.cpp
#	src/rail_gui.cpp
#	src/road_gui.cpp
#	src/saveload/saveload.cpp
#	src/screenshot_gui.cpp
#	src/sound/win32_s.cpp
#	src/statusbar_gui.cpp
#	src/strgen/strgen.cpp
#	src/table/newgrf_debug_data.h
#	src/timetable_gui.cpp
#	src/toolbar_gui.cpp
#	src/town_gui.cpp
#	src/vehicle_gui.cpp
#	src/video/sdl2_v.cpp
#	src/video/sdl_v.cpp
#	src/viewport.cpp

src/screenshot_gui.cpp

@@ -84,7 +84,7 @@ void ShowScreenshotWindow()
 
 void SetScreenshotWindowHidden(bool hidden)
 {
-	ScreenshotWindow *scw = (ScreenshotWindow *) FindWindowById(WC_SCREENSHOT, 0);
+	ScreenshotWindow *scw = dynamic_cast<ScreenshotWindow *>(FindWindowById(WC_SCREENSHOT, 0));
 	if (scw != nullptr) {
 		if (hidden) {
 			scw->SetDirtyAsBlocks();